Physical space became an important notion for those who began to think
more about ubiquitous, pervasive, and embedded devices. However, they
sought to shift attention from place to space, implying that the social/psycho-
logical space had to be considered in addition to the physical place (Dourish,
2002). These notions are likely to become still more important as varied sensors
become more common. Sensors to activate doors in supermarkets or faucets and
hand-dryers in bathrooms are first steps, but newer sensors that detect and
monitor human activity seem likely to proliferate. The goals are often positive,
such as safety, security, or healthcare, but threats to privacy, dangers of errors,
and the need to preserve human control will have to be considered carefully.